The G77 group of 130 developing nations blamed Obama for "locking the poor into permanent poverty by refusing to reduce US emissions further."

"Today's events are the worst development for climate change in history," said a spokesperson.

Pablo Solon, Bolivian ambassador to the UN, blamed the Danish hosts for convening only a small group of countries to prepare a text to put before world leaders. "This is completely unacceptable. How can it be that 25 to 30 nations cook up an agreement that excludes the majority of the 190 nations."

But rich countries said that developing countries had wasted too much time on "process" rather than the substance of the talks. An epic stand-off over whether to ditch the Kyoto protocol's legal distinctions between developed and developing countries and their obligations to cut their emissions caused a huge delay to the negotiations.

But Martin Khor, director of the South Centre, an intergovernmental think tank for developing countries said, "Developing countries are very disappointed because they've invested a lot of time in the documents they're negotiating here."

Politicians from all corners of the world were blamed widely for not setting ambitious enough targets to counter climate change. "They refused to lead and instead sought to bribe and bully developing nations to sign up to the equivalent of a death warrant. The best outcome now is no deal," said Tim Jones, climate policy officer from the World Development Movement.

China's prime minister, Wen Jiabao, blamed a lack of trust between countries: "To meet the climate change challenge, the international community must strengthen confidence, build consensus, make vigorous efforts and enhance co-operation."

But indigenous Bolivian president Evo Morales blamed capitalism and the US. "The meeting has failed. It's unfortunate for the planet. The fault is with the lack of political will by a small group of countries led by the US," he said.

Even veterans of previous environmental negotiations were disappointed. "Given where we started and the expectations for this conference, anything less than a legally binding and agreed outcome falls far short of the mark," said John Ashe, chair of the Kyoto protocol talks.